Histocompatibility antigens in patients with hepatocellular carcinoma and their relationship to chronic hepatitis B virus infection in these patients.

Although hepatocellular carcinoma is probably caused by one or more environmental carcinogens, a genetically determined susceptibility to the development of the tumor has not been excluded. In looking for such a predisposition, we have compared the histocompatibility antigens (HLA) of 102 southern African blacks with histologically proved HCC with those of 208 healthy blacks. The standard two-stage lymphocyte microcytotoxicity method was used to test for 40 antigens: 17 in the A locus, 20 in the B locus, and 3 in the C locus. None of the HLA antigens had a frequency that was significantly different in the patients and the controls. A close association undoubtedly exists between chronic hepatitis B virus infection and hepatocellular carcinoma. If this virus is proved to be oncogenic with respect to hepatocellular carcinoma, a genetic predisposition to the hepatitis B virus carrier state may have an indirect bearing on the etiology of the tumor. Sera from the hepatocellular carcinoma patients were therefore tested for hepatitis B virus markers (HBV surface antigen and antibody against HBV core antigen), and these were related to the patients' histocompatibility antigens. None of the HLA antigen frequencies was significantly different in the surface antigen-positive and the surface antigen-negative patients. As 88% of the patients were anticore positive, no meaningful correlation could be carried out with this marker. Analysis of histocompatibility antigens thus failed to show evidence of a genetic predisposition either to hepatocellular carcinoma or to chronic hepatitis B surface antigenemia in patients with this tumor.